Reeling from the deaths of his only daughters, Lisa and Samantha, in the World Trade Center terror attacks, bookbinder and poet David Egan put his agony into words.

Two years later, he has nearly completed a stirring collection of his poetry aimed at comforting others whose lives, like his, were shattered that sunny September morning.

The intensely private Egan has, for nearly two years, declined to speak publicly of his loss – preferring instead to pour himself into the words he hopes will help others heal.

But in their first major newspaper interview, David and his wife, Elizabeth, spoke with The Post of the daily issues that haunt them and other WTC families – the same trials that comprise the core of Egan’s poetry.

Among them: struggles with suicidal thoughts; frustrations over still-unrecovered remains; and everyday reminders – a favored sweater or old pair of shoes – that brings grief rushing back.

Egan writes for the survivors who have found new loves, and for those who argued – or left words unspoken – before their spouses headed off to work that day, never to come home.

“There are so, so many issues attached to that day,” Egan said. “And often times people do not broach the subjects to others – or to themselves, and that’s hardly healthy. So I took a hard look at things that weren’t being dealt with that needed to be.

“There is a universality about them – and my hope is that in them, someone finds some solace.

“I also want people to know that we still have a long way to go.”

David and Elizabeth’s girls were among the 658 Cantor Fitzgerald employees killed when a plane slammed into the north tower just under the brokerage’s offices on the 101st through 105th floors.

Lisa, 31, worked as a human-resources manager, while Samantha, 24, was a personal assistant in the finance department. Samantha had just returned from a stint working for Chances for Children, a nonprofit group founded by Sarah Ferguson, Duchess of York. The sisters were among a staggering 20 sets of siblings lost by the close-knit Cantor firm.

“They were really close, even with a seven-year age difference,” Elizabeth said of her daughters. “Lisa was one of those little girls who always wanted a baby sister, and when she got one, that was it. And Samantha looked up her.”

With heartbreaking candor, the Egans described a grief that has sometimes threatened to overwhelm them. Both have entertained thoughts of suicide.

“It’s run through my mind, my wife’s mind, more than once,” said David. “And you revisit that . . .”

“. . .often,” said Elizabeth, finishing the thought in a whisper.

Then came reports in the media that some who’d lost loved ones had acted on similar thoughts, taking their own lives.

“I didn’t know those people personally,” David said of the post-WTC suicides. “But I knew too well what they were going through. I thought, ‘If only I had been able to talk to them for a minute . . . “

The suicides, and the Egans’ personal struggles, are the basis for David’s poem, “The Offering,” a heartfelt plea which begins:

Stay with us yet a little while,

We know as well as you your pain.

Walk with us just another mile,

And then, another mile again.

“If my daughters were sitting right here,” said David, “neither one would say, ‘Join us.’ Not only is it not a viable option, it doesn’t resolve anything.”

The Egans, native New Yorkers who now live on Long Island’s North Shore, have one remaining child, son Brendan, 29.

A Marine Corps corporal, Brendan shipped out in the initial strike in the war on terrorism – and just returned after five months in Iraq. Most days, said Elizabeth, it is Brendan’s family, which now includes the Egans’ first grandchild, that holds her together.

“It’s an ongoing struggle,” she said.

“We have a nice home, but the people we want to share it with are gone. We have our son, and our new granddaughter, and that is what keeps me here.”

Elizabeth’s pain-etched face breaks into a fleeting smile as she talks about her new granddaughter.

“Her birth is a mixed blessing,” she said, wiping away tears.

“How my girls would have adored her – they would have been completely ga-ga. And I feel sorry for the baby, because she can’t know what she’s missing, but I do: That this little girl will never know the love those two would have showered on her.” For Elizabeth, the baby is also a reminder of the grandchildren her girls hoped to give her. At Cantor alone, 46 fiancées lost their partners-to-be – Samantha Egan was engaged to be married. Her parents know – and hope – her fiancé will find new love.

“I have heard many people speak about this, and it’s one of the things that bothers and disturbs them deeply,” said Egan, who addresses the topic in “Forgive Me, Love,” writing:

“I wear you daily on my soul

Do not think ill of me

If I should do this thing

I only ask to lay to rest

The future that we planned

But can no longer act upon

Not any of the past that was our time

Notes David Egan: “This is such a difficult situation, but we need to think about it, because it is a natural facet of life.”

In the days following the attacks, news accounts were rife with stories of spouses who had argued – or were too preoccupied to say goodbye – when they left their homes Sept. 11.

“You hear all the anguish and regret from people who saw spouses off to work, after having exchanged ugly words – and then they never spoke to them again,” said David. To that end, he penned the emotionally wrenching “Forgive Yourself.”

“It’s the ‘what-ifs’ and the ‘if onlys’ that haunt you,” said Elizabeth, who spoke to her daughters daily, and whose usual 9 a.m. phone call with them never took place that day.

Meanwhile, some of Egan’s work carries an undercurrent of his feelings of how politicians and planners have interacted with the WTC families.

The recent closing down of DNA-testing operations at Fresh Kills – where remains were taken for identification – saddened and angered both Elizabeth and David. “We know too many people who haven’t recovered remains,” said David. Remains for only about half the 2,741 victims have been recovered.

Overwhelmed by the staggering numbers of those still unrecovered, Egan writes:

“Fresh Kills/The name is everything

Once/it spoke of water/A channel to the sea

That rose and fell

Now/The stream is steady/in its flow

A rippling tide of human pain/that floods the heart/And will not ebb”

While her husband has found a mission in his writing, Elizabeth makes her way “the best I can.”

“There is no ‘moving on, “‘ she said. “Every day, it’s missing them more. A million times a day, still, I go to the phone to call them. I remember some little thing I want to tell them. “You find ways to put it aside – to keep it from consuming you,” she said. “I try to keep busy, moving from x to y to z. But it’s always there.”

Still, said the couple, they are “overwhelmed by the outpouring of compassion” showered on them. David has tried to return the favor through his words.

He has completed 10 poems and is “polishing up” 16 more. He has spoken with publishing houses, but if he doesn’t find one, he will put out the book himself. “I will be satisfied if these poems help people to heal – because, God knows, we could use it,” he said.

Here are excerpts from poems written by David Egan:

FRESH KILLS

… But who is there to hear?

The politicians and the

Moguls of the land

Don’t journey here

Even now

their pilgrimage to sacred ground

has ceased

And they cast lots

to parcel out the spoils.

They do not speak

of what was taken

from our midst

And left

to feel the brunt

of wind and rain

without recourse …

LAMENTATION

If I could but reach across this vale of grief

And hold you once more by the hand

If I could but once more know relief

To hear your voice, and once again command

Your presence with my own.To know

You safe from worldy harm and strife.

Just one more time that I might show

Again the love for you, and what life

Holds in store unbattered by the storm

That rages through another’s world. …

THE SILENCE

Once

there was a dream unfurled

A sweet unfolding now

of heady joy

Of triumph

and of pomp

The promise of what gifts

life held in store

With raucous shouts

of victory

Expelled in trendy bars

Or quiet conversation

held in homes

beneath the spotlights

in the dens

That lay bare

all the victor’s spoils

from boardroom’s battlefield

They regaled us

and each other

with their tales

of praise and conquest

Hard won

or easy jousts

In the lists of corporate America

Talent fueled their quests

and filled out days and ears

with sonorous exclaim

And filled our homes

with everything

their presence had to share

They were a bright

effusive lot

A paean in the euphony of life …

THE OFFERING

… . I have no answers that you do no entertain, Save one perhaps, and that one will remain; To sit or walk with me as is your lot. I shall not hold you if you wish it not, But know my arms are here and empty tool.I know what loss has caused you to go through. I cannot tell you when the darkness Lifts, nor when the burden that does press Upon your heart shall find relief. Nor can I tell you when the grief Which fills your every waking hour, Shall pass itself unto a higher power. So if you can but spare yourself a while, Come sit with me or walk with me a mile.